Frequencies for first 10,000 rows of hmo variable in nhamcsopd1994 dataset : expected | source of | payment-hmo | /oth | prepaid | Freq. Percent Cum. ------------+----------------------------------- 0 | 8,892 88.92 88.92 1 | 1,108 11.08 100.00 ------------+----------------------------------- Total | 10,000 100.00 by Jean Roth , jroth@nber.org , 28 Mar 2016